Marybeth will be induced tonight.

[sst4270]

Thought you all might like to see this.
Her name is Marybeth and I built her for the lead guitarist in my band.

-Steve

PS Cabinet will be built tomorrow and Friday (hopefully) for a gig Friday night if she proves to be stable tonight. The wood is already cut.

[Allynmey]

Nice! What have you done for mods...looks like all kinds of cool stuff!

[sst4270]

It's an express with Power Scaling and Dual Bias Mod with meter jacks. Similar to Fisherman's but with a different layout.

Steve

[keithrick]

Steve, Nice amp! Is that the london power scaling?

[sst4270]

Keithrick,

Spalding is right around the corner. I'm in Ferndale.
I've been in this area since the mid-70's. It would be a pleasure to meet someone else into this "hobby".

Steve

[Fischerman]

Nice! Looks familiar in many ways. I think I like your layout better, I originally was going to use the Ceriatone power supply board and then modify it...so I based my layout on that constraint...then ended up building my own boards anyway but didn't completely redo the layout.

Maybe it's just my amp, and I'll be posting some clips soon showing this, but I can get like, 90% of the cranked tone just by using the Master Volume (however, my MV is different than the one called out in the power scaling schematic)...using the power scaling and getting the power tubes distorting does make it a little better...and it feels different.

Man, I soooo wish we could compare our amps in person...I'm sure I'd learn something. Did you keep everything else 'stock'? I ended up changing the preamp quite a bit and also tweeking the PI.

Are you using the SB switch? Mine is a DPDT switch that just connects the OT center tap and screens to the appropriate B+ nodes...with a .01uF/1kv cap across each switch to prevent pops. It's silent and works well but the sound comes on/goes off extremely abruptly...no fading.

[Paul86]

Is this a great forum or what? Congratulations on a great looking amp! How about some clips?
Also, how much dinero for the whole thing?

[sst4270]

After finding some mistakes in my wiring Marybeth is officially alive as of 1:00 P.M. Sunday March 18, 2007.

The PS/Drive Compensation works great. The dual bias pots & meter jacks are a great addition. It allows me to adjust bias on the power tubes independently eliminating the need for matched tubes even though mine were matched already. Bias set to |30mA| per KF's Trainwreck pages. As I begin to fine tune it to my guitarist's tastes I may adjust the bias.

I have a question for you guys...

I get increased "hum" as my hand approaches the volume knob to adjust. It goes back to a "normal" level of hum and hiss once adjusted.
Does this seem like a ground path issue? Or have you all experienced the same issue with your amps?

Any comments would be appreciated.

I'll be building the cabinet this week and I'll post finished pictures afterwards.

Steve

[lastwinj]

I get increased "hum" as my hand approaches the volume knob to adjust. It goes back to a "normal" level of hum and hiss once adjusted.
Does this seem like a ground path issue? Or have you all experienced the same issue with your amps?

Steve

snip the bright switch out. should eliminate most of that.

germ

[paddy]

I get increased "hum" as my hand approaches the volume knob to adjust. It goes back to a "normal" level of hum and hiss once adjusted.
Does this seem like a ground path issue? Or have you all experienced the same issue with your amps?

I had the same problem with my Liverpool build.
A piece of .55mm sheet metal placed under the chassis
fixed it for me.

cheers
paddy

[sst4270]

My guitarist came over tonight to try her out. Wow! These really are amazing amps. He played through a very modified Kramer and a Mesa Boogie cabinet. He says he can't wait to play it with his Les Paul thru his Marshall cab.

Keithrick... If you want to hear this thing we'll be playing at the Pt. Pleasant beach bar in Glen Burnie on the 7th of April for their season opening.

Thanks for all the help you guys. The cover on the bottom greatly reduced the noise from the volume knob.

I must agree that this is an amazing amp. "Very articulate" "Amazing sustain" & incredibly loud. The brightness that so many of you mention is easily controlled I think via the BR sw, presence, and tone controls.

The best thing is it's ability to go from fairly clean to mean and dirty just using the guitar volume without much change in volume.

I highly suggest the Power Scaling mod as it maintains the cranked tone down to bedroom levels. It was a little expensive from London Power, but I think well worth it. Especially for gigging purposes when volume changes become a necessity as the room changes. You won't have to sacrifice tone.

-Steve

PS Finished pictures will follow by Friday or Saturday I think.

[mrusso]

Wow is right! I am the guitarist that Steve built Mary Beth for (named after my wife). I cannot wait to open her up at the Point Pleasant gig, will provide a more extensive review after that. This amp is what my (modified) Marshall wants to be when it grows up!!!